/*
 * Symphony - A modern community (forum/SNS/blog) platform written in Java.
 * Copyright (C) 2012-2018,  b3log.org & hacpai.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.b3log.symphony.event;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.time.DateUtils;
import org.b3log.latke.Keys;
import org.b3log.latke.event.AbstractEventListener;
import org.b3log.latke.event.Event;
import org.b3log.latke.event.EventException;
import org.b3log.latke.ioc.inject.Inject;
import org.b3log.latke.ioc.inject.Named;
import org.b3log.latke.ioc.inject.Singleton;
import org.b3log.latke.logging.Level;
import org.b3log.latke.logging.Logger;
import org.b3log.latke.model.Pagination;
import org.b3log.latke.model.User;
import org.b3log.latke.service.LangPropsService;
import org.b3log.symphony.model.*;
import org.b3log.symphony.service.FollowQueryService;
import org.b3log.symphony.service.NotificationMgmtService;
import org.b3log.symphony.service.RoleQueryService;
import org.b3log.symphony.service.UserQueryService;
import org.b3log.symphony.util.Escapes;
import org.b3log.symphony.util.Symphonys;
import org.json.JSONArray;
import org.json.JSONObject;

import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Sends article add related notifications.
 *
 * @author <a href="http://88250.b3log.org">Liang Ding</a>
 * @version 1.3.4.14, Jan 30, 2018
 * @since 0.2.0
 */
@Named
@Singleton
public class ArticleAddNotifier extends AbstractEventListener<JSONObject> {
	// 添加文章,此字段是从EventTypes移动至此
	public static String ADD_ARTICLE = "Add Article";

	/**
	 * Logger.
	 */
	private static final Logger LOGGER = Logger.getLogger(ArticleAddNotifier.class);

	/**
	 * Notification management service.
	 */
	@Inject
	private NotificationMgmtService notificationMgmtService;

	/**
	 * Follow query service.
	 */
	@Inject
	private FollowQueryService followQueryService;

	/**
	 * User query service.
	 */
	@Inject
	private UserQueryService userQueryService;

	/**
	 * Language service.
	 */
	@Inject
	private LangPropsService langPropsService;

	/**
	 * Role query service.
	 */
	@Inject
	private RoleQueryService roleQueryService;

	@Override
	public void action(final Event<JSONObject> event) throws EventException {
		final JSONObject data = event.getData();
		LOGGER.log(Level.TRACE, "Processing an event [type={0}, data={1}]", event.getType(), data);

		try {
			final JSONObject originalArticle = data.getJSONObject(Article.ARTICLE);
			final String articleId = originalArticle.optString(Keys.OBJECT_ID);
			final String articleAuthorId = originalArticle.optString(Article.ARTICLE_AUTHOR_ID);
			final JSONObject articleAuthor = userQueryService.getUser(articleAuthorId);
			final String articleAuthorName = articleAuthor.optString(User.USER_NAME);

			final Set<String> requisiteAtUserPermissions = new HashSet<>();
			requisiteAtUserPermissions.add(Permission.PERMISSION_ID_C_COMMON_AT_USER);
			final boolean hasAtUserPerm = roleQueryService.userHasPermissions(articleAuthorId,
					requisiteAtUserPermissions);
			final Set<String> atedUserIds = new HashSet<>();

			if (hasAtUserPerm) {
				// 'At' Notification
				final String articleContent = originalArticle.optString(Article.ARTICLE_CONTENT);
				final Set<String> atUserNames = userQueryService.getUserNames(articleContent);
				atUserNames.remove(articleAuthorName); // Do not notify the author itself

				for (final String userName : atUserNames) {
					final JSONObject user = userQueryService.getUserByName(userName);

					if (null == user) {
						LOGGER.log(Level.WARN, "Not found user by name [{0}]", userName);

						continue;
					}

					final JSONObject requestJSONObject = new JSONObject();
					final String atedUserId = user.optString(Keys.OBJECT_ID);
					requestJSONObject.put(Notification.NOTIFICATION_USER_ID, atedUserId);
					requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, articleId);

					notificationMgmtService.addAtNotification(requestJSONObject);

					atedUserIds.add(atedUserId);
				}
			}

			final String tags = originalArticle.optString(Article.ARTICLE_TAGS);

			// 'following - user' Notification
			if (Article.ARTICLE_TYPE_C_DISCUSSION != originalArticle.optInt(Article.ARTICLE_TYPE)
					&& Article.ARTICLE_ANONYMOUS_C_PUBLIC == originalArticle.optInt(Article.ARTICLE_ANONYMOUS)
					&& !Tag.TAG_TITLE_C_SANDBOX.equals(tags)
					&& !StringUtils.containsIgnoreCase(tags, Symphonys.get("systemAnnounce"))) {
				final JSONObject followerUsersResult = followQueryService.getFollowerUsers(
						UserExt.USER_AVATAR_VIEW_MODE_C_ORIGINAL, articleAuthorId, 1, Integer.MAX_VALUE);

				final List<JSONObject> followerUsers = (List<JSONObject>) followerUsersResult.opt(Keys.RESULTS);
				for (final JSONObject followerUser : followerUsers) {
					final JSONObject requestJSONObject = new JSONObject();
					final String followerUserId = followerUser.optString(Keys.OBJECT_ID);

					if (atedUserIds.contains(followerUserId)) {
						continue;
					}

					requestJSONObject.put(Notification.NOTIFICATION_USER_ID, followerUserId);
					requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, articleId);

					notificationMgmtService.addFollowingUserNotification(requestJSONObject);
				}
			}

			final String articleTitle = Escapes.escapeHTML(originalArticle.optString(Article.ARTICLE_TITLE));

			// 'Broadcast' / 'Book' Notification
			if (Article.ARTICLE_TYPE_C_CITY_BROADCAST == originalArticle.optInt(Article.ARTICLE_TYPE)
					|| (Article.ARTICLE_TYPE_C_BOOK == originalArticle.optInt(Article.ARTICLE_TYPE)
							&& !articleAuthorName.equals("book_share"))) {
				final String city = originalArticle.optString(Article.ARTICLE_CITY);

				if (StringUtils.isNotBlank(city)) {
					final JSONObject requestJSONObject = new JSONObject();
					requestJSONObject.put(Pagination.PAGINATION_CURRENT_PAGE_NUM, 1);
					requestJSONObject.put(Pagination.PAGINATION_PAGE_SIZE, Integer.MAX_VALUE);
					requestJSONObject.put(Pagination.PAGINATION_WINDOW_SIZE, Integer.MAX_VALUE);

					final long latestLoginTime = DateUtils.addDays(new Date(), -15).getTime();
					requestJSONObject.put(UserExt.USER_LATEST_LOGIN_TIME, latestLoginTime);
					requestJSONObject.put(UserExt.USER_CITY, city);

					final JSONObject result = userQueryService.getUsersByCity(requestJSONObject);
					final JSONArray users = result.optJSONArray(User.USERS);

					for (int i = 0; i < users.length(); i++) {
						final String userId = users.optJSONObject(i).optString(Keys.OBJECT_ID);

						if (userId.equals(articleAuthorId)) {
							continue;
						}

						final JSONObject notification = new JSONObject();
						notification.put(Notification.NOTIFICATION_USER_ID, userId);
						notification.put(Notification.NOTIFICATION_DATA_ID, articleId);

						notificationMgmtService.addBroadcastNotification(notification);
					}

					LOGGER.info("City [" + city + "] broadcast [users=" + users.length() + "]");
				}
			}

			// 'Sys Announce' Notification
			if (StringUtils.containsIgnoreCase(tags, Symphonys.get("systemAnnounce"))) {
				final long latestLoginTime = DateUtils.addDays(new Date(), -15).getTime();

				final JSONObject result = userQueryService.getLatestLoggedInUsers(latestLoginTime, 1, Integer.MAX_VALUE,
						Integer.MAX_VALUE);
				final JSONArray users = result.optJSONArray(User.USERS);

				for (int i = 0; i < users.length(); i++) {
					final String userId = users.optJSONObject(i).optString(Keys.OBJECT_ID);

					final JSONObject notification = new JSONObject();
					notification.put(Notification.NOTIFICATION_USER_ID, userId);
					notification.put(Notification.NOTIFICATION_DATA_ID, articleId);

					notificationMgmtService.addSysAnnounceArticleNotification(notification);
				}

				LOGGER.info("System announcement [" + articleTitle + "] broadcast [users=" + users.length() + "]");
			}
		} catch (final Exception e) {
			LOGGER.log(Level.ERROR, "Sends the article add notification failed", e);
		}
	}

	/**
	 * Gets the event type {@linkplain EventTypes#ADD_ARTICLE}.
	 *
	 * @return event type
	 */
	@Override
	public String getEventType() {
		return ADD_ARTICLE;
	}
}
